I was running a fully clean boot, i.e. with startup-sequence disabled as I didn't want anything to interfere. I also did not have any peripherals or PCMCIA card connected.
I was paying attention to centering and leveling the socket properly prior to installation, applying light force in the beginning to avoid damaging the socket, and not applying high force until it was needed. There was a lot of creaking noises as it went down, but no click or locking feeling. Looking at the socket, no damage can be seen (don't know if you can see it if it happened?). I pushed as hard as I felt was safe as the motherboard was bending down quite a bit.
I will post some pictures of the installation tonight.